Phantom of the Underground
by PotterPhantomKitten
Summary: The Underground's opera house has been reopened, and with it are the rumors of the Phantom that inhabits it. Hidden from sight, red eyes glinting behind her mask... and secretly infatuated with the opera house's newest star, Asriel Dreemurr. But obstacles stand in Chara's way—her past, her disfigurement, and Asriel's childhood friend, Frisk. AU inspired by The Phantom of the Opera.
1. Prologue: Voice in the Dark

**A/N:** **Hi there, fellow Undertale fans! As a note to start this off, you don't need to be familiar with Phantom of the Opera to understand this, it can stand on its own. There will be some comparable elements, both character and music-wise, but at the heart of the story is the Undertale aspects.**

 **Basically, I've loved Phantom of the Opera since the 2004 movie came out, and I've gotten back into my obsession with it, just as with Undertale. Then a few days ago, as I was dwelling on my ships for Undertale, and thinking how I mainly ship Chasriel but I love Frasriel too (not sure if that's the right term for FriskxAsriel, haha), I thought, "Hey, Phantom of the Opera is a love-triangle thing I really love, and Chara would make a perfect Phantom! Why don't I make it about her, Asriel, and Frisk?" So the thought of doing that filled me with determination. :)**

 **Basically, in this AU, humans and monsters are both integrated into society, the opera house/theatre is in the Underground, and the backstories of some of the characters are thus a bit different. Well this be a direct Phantom-of-the-Opera-with-Undertale-characters thing? Nope, and there will be some storyline twists and background changes, as well as a few surprise characters. ;) But as far as core character similarities go, basically Chara is like Erik/the Phantom, Asriel is like Christine, and Frisk is like Roaul—for the record, I definitely ship ChristinexErik PotO-wise, but I love Frisk too.**

 **Finally, regarding music—I've been watching the Undertale the Musical videos recently, and Phantom of the Opera is a musical. This won't really be a song fic, though I may insert one or two songs in there, and if I do, it will likely be to the tune of an Undertale song. Again though, there likely won't be many, if any at all. Heck, I may include Mettaton's. XD**

 **With all that said, on with the fic! :)**

 **Disclaimer: I don't own Undertale, or Phantom of the Opera.**

* * *

The few remaining occupants of the Underground Opera House knew that within 12 hours, the atmosphere would be transformed from a silent stage to a building that blazed with life, both human and monster.

To the casual observer, a visitor would only think there was one remaining monster in the Opera House, an orange cat-like being called Burgerpants in the backstage rafters. He tugged on the rope to hoist the wooden plank upward, adjusting his supplies to make sure that everything was nicely polished and ready for the next day.

"Can't have any of the actors getting splinters tomorrow," Burgerpants muttered, turning a careful eye to the floorboards as he walked onto the upper layer where curtains and backdrops could be dropped down for each show as needed. He let out a laugh, somewhat bitter but with a twinge of anxiety. "I should be one of them," he exclaimed, raising his voice to fill the silence and keeping his ears trained for any suspicious sounds. "But no, they said 'you need to work on your act, you're bette suited for backstage work'." His voice took on a mocking tone before he shook his head in defeat. "Maybe the new managers will be nicer to me."

 _"I would hope so if I were you. Luckily I'm not."_

The voice startled Burgerpants so much that he dropped the hammer just inches from his foot, his cigarette also dropping to the floor. Leaping up a little, his fur standing up on end both from the shock of nearly having a hammer driven into his foot and the voice he heard. Hands shaking, he gripped the hammer as a weapon, eyes and ears trained as he fought against the urge to swing it wildly around.

Not that an action like that would do anything against a ghost.

Burgerpants flinched a little, looking up in the rafters as the smallest of scraping noises reached his ears, though no other voice spoke. Part of his mind thought it could just be a rat, but he knew better, Momentarily pocketing his cigarette, he trained his attention up to the rafters. He knew he had heard something—some _one_ —and he knew _exactly_ who it was. Even if some refused to believe _she_ even existed.

With the opera house under new management, maybe it would be different. Perhaps he could get that Dr. Alphys to set up cameras...

But the monster shook the idea out of his head the moment the thought came to him. Encroaching on the staff's privacy would be a bad idea,and who was to say she would even show up on film? The years he had worked here as the janitor didn't give him many clues, and he already had more than enough situations where that thing would reach into his mind and invade his dreams.

At least members of the opera's staff knew, a good number of them believing. The patrons, though...

But having others who believed the rumors about the Phantom wouldn't help him here. Right now it was just him and the ghost. And not a friendly ghost like Napstablook. Blooky and that _thing_ were of a different incorporeal nature entirely, or so Burgerpants believed. Blooky was a friendly ectoplasmic manifestation, and while it was true he had self-esteem as low as the bottom of the ocean, he wouldn't hurt a fly. The Phantom, on the other hand... Burgerpants got the feeling that she could kill him as soon as look at him, even though those times when he did sense her nearby, it was nothing more than a voice of a few short words and a momentary flicker of red eyes glinting in the dark like their owner was about to leap out and devour his SOUL any moment.

Swallowing, he tried to ignore his racing thoughts and mounting fear, only to have the voice speak again.

 _"So,"_ the voice said thoughtfully, so quiet it could almost be mistake for a conjuring of the imagination. _"Opening again tomorrow."_ A light giggle echoed. _"About time."_

Burgerpants stood up straight, his fingers clenching tight around the hammer. If this Phantom was going to try to bully him, he wasn't about to let it—at least that was what he tried to tell himself. If only one of the others was here, then he wouldn't seem so crazy.

"I know you're there," he called, trying to sound braver than he felt. But though his voice was stronger than he had expected, his shaking legs gave away his fear. "I know you're there you... you phantom..." To call _her_ a human or monster would be an insult to both races. If that _thing_ had been one or the other, long ago, she wasn't any more. A demon would probably be the best word to describe her, but the thought of doing so only further terrified him. "Come out, Phantom."

But nobody came.

After a minute of silence, hear and seeing no indication that the being was still present, Burgerpants turned away from the ceiling and nervously began humming to himself as he swept the floor. Even so, he couldn't shake the feeling that eyes were watching him, melted in the shadows.

He wasn't wrong.

In fact, such a tactic was practically the owner's area of expertise. That, and scaring the living daylights out of people on occasion when she was bored. Whether unintentionally or not.

The figure scrunched her eyes shut for a moment, unseen as always. Her gaze briefly flickered downward to where the empty stage could be seen, looking as if it had been abandoned for a few years rather than hours. Quiet and boring, but good for giving a good scare to anyone who happened to be out after hours.

Burgerpants was always good for a laugh. Everyone thought the 19-year-old was a bit insane anyway, it wasn't like anyone unfamilar with the opera house would take his claims of a "phantom" as being worth serious investigation. But then, no one had really bothered her for years. Why start now?

She hoped that, perhaps, the grand re-opening would bring a change around this place. Scaring the jumpy janitor could only go so far for entertainment, and the new furnishings and props would certainly bring this area to life again. Maybe even some more fresh talent. Supposedly a few members of the choir were set to try for solos.

But she could only think of one she hoped to see there. Even if he'd never really _see_ her—but hearing his voice again would at least be a blessing in this maddening silence..

* * *

 _"I can come back."_

 _"You won't be able to until it re-opens again. It's only for a few months." The words hurt to say, but she wasn't about to let any weakness show in her voice. She had many traits, but weakness was certainly not one of them. "Just remember everything I've taught you."_

 _"Maybe we could meet outside the—"_

 _" **No!** "_

 _She had immediately regretted the forcefulness of her response when she saw the young goat-monster leap back slightly at her tone. She quicly tried to recover herself and try again—given that he had only heard her voice, she didn't want their bond to be tainted by a stray outburst. "I have to stay here. I'll meet you once the place re-opens."_

 _"But—"_

 _"Please. For me."_

 _There was a pause. "Alright."_

 _"Promise?"_

 _"... I promise."_

 _The reply was reluctant, but for her, it was enough for the time being._

* * *

Bringing her thoughts back to the present moment, the spectre brushed her brown hair out of her face, the strands of hair lightly brushing over the mask. The red light from her eyes gave almost ethereal glow to the wooden beam that she lay against, but by the time she heard that pesky janitor turn to look up, she had gone.

Moving silently through the rafters and crevices of the building, descending from the stage and venturing deeper than where anyone else dared go, a smile crossed her face.

Tomorrow the Underground Opera would finally be open again.

* * *

 **A/N: Yup, Burgerpants is the basically like Joseph Buquet in this AU, he was just the first one that popped into my head for that—I'm actually surprised myself at how much of a role BP got in this first chapter, it wasn't my original intention but I just kind of ran with it. XD And don't worry, Asriel, Frisk, and the rest will appear in the next chapter. And for those who are Phantom of the Opera fans, see if you can guess who will be like which Phantom characters, because there will be at least a few parallels, though I have plenty of twist ideas for this story. ;) Anyway, see you next chapter and reviews are appreciated!**


	2. New Management

**A/N:** **Thanks for the reviews on the first chapter, guys—nice to see there's even a few who like it who haven't even read/watched PotO before, that means I've done my intended job correctly! So, now that the opera house is open, we'll see a lot of the rest of the bunch, so be prepared for characters galore!**

 **And in case you're wondering why a certain character aside from Chara, Asriel and Frisk is now in the main character list, well, you'll see this chapter, as a bit of a twist from the exact Phantom scenario. ;) Onward!**

* * *

Though the morning sun couldn't be seen Underground, the sparkling stones on the ceiling seemed to shine brighter when the morning arrived. As if to not only welcome the morning, but also announce the grand re-opening of the monsters' greatest theater establishment. At least, that was how Chara saw it—metaphorically speaking, as she could only guess. It had been ages since she had truly seen the outside.

Wanting to get a better view at the ones that were coming in, hoping to see her student, Chara crept down toward Box Five at the edge of the stage, hiding behind the curtains of its confines. For once, the resident Opera Ghost was feeling... well, not exactly happiness, but more anticipation. Now that the Opera House was open once again, she was sure to see a few familiar faces—unfortunately Mettaton being one of them, "star for five seasons" as he was. But the one she longed to see more than any other was Asriel Dreemurr, even if he wouldn't get to see her in turn.

Sure enough, Asriel was one of the first to arrive with his mother, Toriel Dreemurr, seeing as she was one of the head staff of the Opera House. What Chara had left of a heart and SOUL leapt the moment she saw her sweatered student, and part of her wanted nothing more than to say hello to the one she missed so much. But alas, the young goat monster hurried to a group of the monsters around his age from the chorus, eager to catch up on how they had been.

Chara frowned. Talking with her secret love would have to come later. But along with her eagerness to see Asriel again, Chara had to admit that part of her anticipation leaned toward the negative. After all, W. D. Gaster was retiring, and she wasn't sure how the two new managers would run the place.

Up until today, W. D. Gaster had been the owner of the Opera House (at least from the perspective of most), but with the re-opening and his retirement came a shift in managerial positions. Of course, that didn't mean that the building would be left without the Gaster family touch...

As W. D. Gaster and his two sons entered the building and headed to the central stage room, the Opera House was already bustling with people. Most were employees and performers from previous seasons, and there was one robot-looking performer who already seemed to be trying out poses near the stage, as if he were made for the spotlight. From her position, Chara noticed that the younger members of the Gaster family seemed to share a sentiment that was close to her own, even though they tried to hide it.

"Not surprised he decided to show up," Gaster said with a light smile before looking at the two shorter skeletons at each side. "Just don't give Mettaton too many compliments to overshadow everyone else and you'll be fine. After all, theater's a group effort, and I know you two are great at group efforts."

"I would hope so," Chara muttered.

"Are you sure about this, Dad?" the shorter, somehow more round-looking skeleton asked as he looked upward at the opera house's ceiling, and at the crystal chandelier that hung above them, shimmering in a thousand crystals and light from the plants of Waterfall. "I mean, Papyrus and me running the place, it's a big job—"

"Nonsense, Sans!" exclaimed the third skeleton of the group, giving his older but shorter brother a noogie. "With your puns and my brilliance, we were born for entertainment! Who better to run a place like this than us?"

"I suppose you're right," Sans admitted with a grin.

"All I ask," Dr. Gaster went on, "is that you run the Underground Opera House so it's just as prosperous as it has been under my care all these years." He turned to face his two sons, the edges of his black cloak curling around his ebony feet. "You've paid attention, haven't you?"

"Sure," Sans said with a laid-back shrug. "We know all the ins and outs. I think we'll be able to handle it."

"Of course we will!" exclaimed Papyrus, enthusiastically putting an arm around his brother's shoulder and seemingly causing all uncertainty to vanish. "I, the Great Papyrus, will ensure that the Underground Opera House will be the greatest musical establishment both the Underground and surface world have ever seen! With free spaghetti every Saturday!"

A small chuckle escaped Gaster's mouth. "Just don't get too out of control. I'll want to check up on your progress, you know."

"We'll call you every day," Papyrus assured with a confident salute, "even if it's just to say hello!"

Gaster's expression slowly shifted to one of unusual severity, as if something was putting him on edge. His eyes too turned above, but more toward toward the boxes, in particular Box Five that overlooked the stage, Chara quickly hiding herself from view.

Seeing no one, the older skeleton turned to his sons once more. "And... don't do anything to anger the Phantom, will you?"

The skeleton brothers blinked.

"You mean that Opera Ghost you mentioned to us before?" Papyrus asked.

"Yes," Gaster affirmed, inclining his head. His thoughts almost seemed to be elsewhere, as if leaving his sons at the mercy of the resident spectre wasn't something he looked to think about too much. After all, her demands could be unpredictable...

"Wait, so she actually exists?" Papyrus asked, looking startled as if said Opera Ghost were going to leap out and attack him at any moment. "I thought you were just joking!"

"Just be careful." Gaster turned his gaze away from his sons and up toward the rafters, then Box Five once more, looking for even the barest hint of a ominous figure overlooking them. He didn't see anyone, but he knew with _her_ one could never tell. "It's rude to talk about someone who's listening."

The brothers looked upward as well. Papyrus didn't look quite as enthusiastic and confident anymore.

Gaster's expression softened. "I didn't mean to frighten you, my sons," he said gently, trying to help them be more at ease despite his own growing misgivings. "The Opera Ghost won't hurt you as long as you don't anger her and do what she says."

"So wait, we're _not_ supposed to do what she says?"

"No, we're supposed to do what she says and not make her mad, Pap," Sans said.

"Oh."

Chara facepalmed. _Great, the new 'managers' haven't been here for five minutes and I can already tell they're incompetent._

"But don't worry, Dad," Sans assured, trying to lighten the mood. "We'll make sure that she won't have a _ghost_ of a chance to bother us."

Papyrus groaned slightly. Typical Sans and his love of puns.

Despite Papyrus's annoyance, the bad pun seemed to lighten the mood just enough for the elder skeleton to be more at ease. "If you have any questions," Gaster said, "feel free to ask Toriel Dreemurr. She knows more about this Opera House than almost anyone."

"Who's Toriel Dreemurr?" Papyrus asked with a frown, adjusting his scarf.

"That would be me."

The Gaster trio turned to see a tall goat monster who was carrying a small letter in her clawed hand, the other at her side. She wore an elegant purple dress that wouldn't look out of place in one of the opera's performances, the symbol of the Delta Rune elegantly stitched onto its surface. Despite the business-like tone of the goat monster's voice, there was kindness and understanding there as well. "Sans. Papyrus. It's so nice to finally meet you."

"It's nice to meet you too, Mrs. Dreemurr!" exclaimed Papyrus, stepping forward and giving the goat monster an excited handshake.

Toriel laughed good-naturedly and returned the handshake. "It's very nice to meet you too."

"Hi," Sans said, lifting his hand in laid-back wave. "Good to meet you, Toriel—I mean Mrs. Dreemurr."

"You can call me Toriel if you'd like," Toriel said with a patient smile. "Mrs. Dreemurr sounds so... formal."

Gaster's expression softened, knowing full well that the reason behind it wasn't just formality. Her husband, Asgore, had died years ago of an illness, leaving her to raise Asriel herself from the time he was 10.

"Will do, Toriel," Sans said with a nod.

Gaster felt for Toriel's plight, but he didn't want to leave for his retirement on a sour note. "Toriel, is that..." he gestured a bony hand toward the note she held tight within her palm.

"Oh, yes," Toriel said, unfolding the letter, "it's actually a message from the Opera Ghost—"

"Really?" Papyrus asked, appearing to sweat. "Um, she's not mad at us, right?"

"How can she be mad, Pap?" Sans inquired. "We just got here."

Toriel glanced over the scrawled letter. "Well, first, she says that you were a good manager, Mr. Gaster, and your presence shall be missed."

Gaster looked surprised at that, but managed a smile all the same. "I didn't realize I'd be missed so much."

Toriel smiled fondly at the older skeleton. "You will, I can assure you of that. The rest of the letter, however," she went on, turning her gaze strictly on Sans and Papyrus," is for you two."

"Us?" Papyrus asked, peering at the note curiously.

Toriel nodded, her eyes scanning over the letter. "First, she wants to welcome you to her Opera House—"

"I thought it was _our_ Opera House now," Papyrus interrupted, looking even more confused.

"I guess we're second-in-command, bro," Sans responded with a shrug.

"And she requests that you keep Box Five empty for her use."

"Consider it done, Mrs. Dreemurr!" Papyrus said with his usual cheerful attitude. He then leaned close to his brother and whispered. "What's Box Five?"

"That overhanging seat area to the right of the stage," Sans whispered back.

"Oh."

"Something else worth mentioning," Toriel added, clearing her throat, "She also says to not forget her salary every month."

"Her salary?" Sans asked. "What salary?"

"We have to pay her?" Papyrus asked, a wary look on his face. "Why does a ghost need a—" At hearing his father clear his throat as if in warning, Papyrus remembered that the Opera Ghost could in fact be listening and quickly moved on. "Uh, how much?"

"Well," Toriel started with hesitation, looking over at Gaster.

The older skeleton monster sighed. "I would give her 20,000 G a month."

"20,000G?!" Papyrus exclaimed, grabbing the note and looking at it for himself. "Are you sure she didn't put an extra zero or two?"

"I know it's a lot," Toriel said sympathetically, "but I don't think it will be too much of a problem. After all, this place is newly opened again, and with Frisk as your newest patron..."

Both of the skeletons looked up at the name.

"Wait, _Frisk_?" Papyrus asked. "Our human friend that Dad introduced us to last year on a business trip? Who bought a house in the Underground now? That Frisk?"

"Do you know of another Frisk?" Toriel asked with amusement.

"Well, no," admitted Papyrus. "So she's coming here?"

"She should be here promptly," Toriel affirmed, her gaze resting on the doors as if thinking that Frisk was going to come in right then as if on cue. "She knows the Opera House is open again." And I know there's a certain someone she'll be wanting to see."

"Who's that?"

"My son Asriel, of course!" Toriel said with a laugh. "He and Frisk were childhood friends." An almost sneaky grin manifested on her face as she lowered her voice, on the off-chance her son might be listening. "Don't tell Asriel she's coming, he has no idea and I want her to surprise him!"

"Speaking of him, Toriel," Gaster added, "how's your son been lately? He looks to be happy reuniting with his chorus-mates."

"Trust me, all he's been talking about for the past week is returning here, so I'll say he couldn't be happier." She turned behind her and called over to the choir group. "Asriel, my child!"

The younger goat monster, sporting a green and yellow striped sweater, turned from his discussion with a somewhat embarrassed look on his face. "Yeah, Mom?"

"Come over here, I want you to meet the new managers!"

 _New managers?_ Asriel couldn't deny that he felt a little nervous at that. He knew Mr. Gaster, of course, but had never met his sons, ad knowing his mother she'd probably want him to sing. _Just don't get too nervous..._

"Asriel, good to see you," Gaster said as the young goat monster stood beside his mother. "I've heard your singing has been improving?"

"I've been trying, sir," Asriel said, trying to look the retiring manager in the eye. "I'm a lot better than I was a few years ago, let's put it that way."

"I'm very pleased to hear that. Maybe you could give my sons here a little performance?"

"Uhh..."

"Oh, don't worry, young one," Gaster said gently with a wave of his hand. "I don't want to put any pressure on you. With that, the older skeleton placed his hands on his sons' shoulders, giving them soft smiles before leaning down and pulling them into a group hug. "Good luck you two. If you need me, I'll be up at the surface for a while, but just a phone call away, If anything goes seriously awry—"

"We'll let you know!" Papyrus affirmed. "But we'll make sure nothing goes wrong!"

"I hope you're right, my sons," Gaster murmured before releasing his hold on the brothers. "I hope you're right." With a fond smile that held a tinge of worry, he turned to leave, his feet slowly clicking on the floor as he walked through the opera house's ornate golden doors. As he glanced backwards once more, the door shut behind him as he disappeared out of sight.

After a few seconds, Papyrus then turned so excitedly to the young goat that his scarf nearly whipped him in the head. "Now can we hear you sing?"

Having had to duck to avoid the wayward scarf, Asriel couldn't help but feel a twinge of nerves creeping up on him again. True, the brothers seemed friendly enough, but.. "Well..."

"Asriel, my child, you sing very well," Toriel said gently, placing a hand on her son's shoulder to encourage him, causing the young goat to turn a bit pink at the praise as she looked at Sans and Papyrus. "He's been taking lessons from a very good teacher."

"Really? Who?" Papyrus's eye sockets widened, his mouth an excited grin as his spine became straight as a ruler. "Is it one of my fans?"

" _In your dreams, numbskull,_ " Chara whispered to herself. She cracked a smile as she reflected on her own words and the nature of the monster in question. " _Heh, 'numbskull'._ "

"You don't have any 'fans'," Sans teased.

"Wh... Well, I..." Papyrus stammered a moment before regaining his usual confidence. "Well I'm co-manager, so I will now!"

Toriel laughed at Papyrus's comment.

"Mom..." muttered Asriel, looking up at her and trying to maintain a shaky smile. In truth, he felt both amused by the more boisterous of the skeleton brothers and a bit anxious at the prospect of performing so soon in front of the new managers. Even if they _were_ W. D. Gaster's sons, and he was one of the kindest monster adults that Asriel knew... "I-I don't know her name," Asriel admitted. "I've never asked... but she's really nice to me!" he added hurriedly.

"Well, then let's hear how well you've been taught!" Papyrus exclaimed excitedly. "I'd love to hear you—"

"I hope you're talking about _me_ ," said a smooth-sounding voice, causing the others in the vicinity to turn. Before them stood a black and pink robot-like being with black hair hanging over one eye. He stood triumphantly and flashed a winning smile, as if he were the star of the show and was willing to flaunt it for all it was worth.

"Oh, um, sorry, Mettaton," Toriel said, trying to smile. "We were actually talking about my son. He was going to sing for us."

"Sing? A kid like him?" Mettaton inquired with a scoff as he crossed his arms. "If you're thinking of having _him_ try to upstage me, there's no chance that will happen! After all, I was the star of our last opera! Or have you forgotten?"

"Really Mettaton, we just—"

But Mettaton had already raced close to the stage's backdrop and starting to sing a song from the Opera's last performance, in an operatic voice that that sounded quite a bit higher than Sans and Papyrus would have expected had they not accompanied their dad before, even for a tenor.

 _"Oh my love,_

 _Please run away._

 _Monster King,_

 _Forbids your stay!"_

Chara scowled, exiting the box as fast as one could blink. True, Mettaton had been the star tenor of the Opera House for the past few years (much to her distaste), but this was her beloved Asriel's time to shine. Not Mettaton's. Intent on getting the obnoxious stage-hog to shut up as soon as possible, she hurried over to the supports for the backdrop, unrolling it as fast as she could with a smug grin. She watched with satisfaction as the replacement backdrop fell on top of the robotic being, knocking him to the ground in a heap from the unexpected weight. She snickered as the former star struggled to pick himself up from the backdrop's covering.

"Uh, are you okay, Mettaton?" Sans asked cautiously as he moved to help the star up, "I mean, it was probably a loose rope, things like that happen—"

But Mettaton interrupted with a sharp glare as he knocked the skeleton's helpful hand away. " _Things like that_ have been happening for several years! Your father didn't stop them from happening, and you two have barely been here five minutes! Sorry to say this, darlings, but I can already tell you're as bad as he is!" He stood tall, his metal arms crossed in a huff. "And until you stop these things from happening, _this thing_ ," he said with emphasis, pointing dramatically to himself, "does not happen!"

With that, he stormed off, the group staring after him as his feet clinked against the floor, making as dramatic an exit as he could.

"... He'll be back," Toriel said with a deadpan expression after a few moments of silence. "The allure of the stage is too much of a draw for him to leave forever." The older goat monster shook her head with a slightly bemused chuckle before turning once more to Asriel. "Go ahead, my dear."

Asriel paused. With all the focus that Mettaton had drawn (as usual) part of him hoped that the new managers and his mother would forget about him performing. But at the same time, he did wan to make his teacher proud. Providing she was here, of course.

"Oh yeah!" Papyrus exclaimed. "Go ahead and sing for us!"

"Give it a shot, buddy," added Sans. "I may be a jokester, but I won't laugh at your singing. I don't have a _bone_ to pick."

Papyrus started muttering something about his brother's pun, but tried to ignore it.

Asriel looked from the skeleton brothers to his mother, then behind him as he noticed a few others were watching him as well. Members of the chorus.

 _Don't get stage fright,_ he thought to himself. _I have to make my teacher proud of me and prove myself to these guys. This is what I've been practicing for, right?_

"Don't be shy, sweetie," Toriel goaded, breaking him out of his thoughts, "you've wanted to perform at the opera these past few months, haven't you?" A gentle smile spread across her face as she nodded at the skeleton brothers. "Here's your chance."

Asriel hesitated at the multitude that was watching him, humming a few bars for experimental purposes. With a curious expression forming, he switched from humming to words, his voice slowly growing stronger as he focused more on the melody and less on the fear that he'd screw up.

" _Think of me._

 _Think of me fondly,_

 _When we've said goodbye..._ "

Sans and Papyrus's mouths dropped open.

The teen goat-monster closed his eyes, focusing more on the melody and less on the slightly nervous tremor in his voice. For once it was nice to be here, and despite the pairs of eyes staring at him the silence was almost relaxing in contrast to the butterflies he felt in his stomach. His voice grew both in volume and confidence.

" _Remember me,_

 _Once in a while, please,_

 _Promise me, you'll try._ "

Above them, hidden behind the stage curtain, the opera house's phantom was entranced by the voice she had been longing to really hear those past few months. Now that the opera house was finally re-open, they could resume their lessons and she'd have Asriel near her again. And with the talent that he clearly had, the entire Underground would soon know of the genius that she had helped him bring out.

Chara slowly let her eyes close for a moment, sighing contentedly as she let Asriel Dreemurr's voice carry her away. She had been in the theatre for more years than she could think of since she started haunting its darkest corners, but she had never heard a voice as gorgeous as his before. It was a blessing to hear it again outside of the memories that she held close.

For a moment, she could forget what she looked like. What she did. She could forget every bad thing in her past and present during those moments when Asriel sang. Seemed like her teaching had paid off.

" _When you find, that once again you long,_

 _To take your heart back and be free,_

 _If you ever find a moment,_

 _Spare a thought for me._ "

"You have a wonderful voice, Asriel Dreemurr..." Chara's voice echoed like a whisper on the wind, and she knew that he was too far away to hear, but even her well-wishes were enough. It seemed that Asriel really had held onto what she had taught him.

As the young goat-monster let the last of the notes fade, the one second of silence afterwards was suddenly interrupted by clapping.

"Bravo! Bravo!" Papyrus cheered. "You're meeting all my singing standards!"

"You did great, kid!" Sans added.

"I always did like your singing."

Asriel immediately opened his eyes at the third voice, his posture faltering a bit as his eyes swung toward the entrance. His best friend Frisk, 18 years old just as he was, was grinning at him, wearing her blue-and-purple sweater that bore a similarity to his own green and yellow one.

His eyes blinked in astonishment before a huge grin spread across his face. "Frisk!"

"Asriel!"

The two new managers practically forgotten, the pair raced to each other and hugged one another tightly, overjoyed by their reunion.

Unseen by them, Chara's peaceful expression was instantly replaced by a mixture of bewilderment and anger. So _that_ was Frisk.

Asriel could feel a blush creeping up on his face, embarrassed at having been heard by his friend as he broke away from the hug. Though in a way, he was secretly glad—if he had known Frisk was there he probably would have felt even more nervous. "I-I-what are you doing here?! I didn't think I'd see you here!"

"Well, you're gonna be seeing a lot more of me, silly!" Frisk chided, ruffling the top of his head playfully. "I'm the new patron here!"

"So wait, you're helping fund the place?"

"Sure am! Though to tell the truth," Frisk added, her grin widening like she was eager to see her old friend's expression, "part of it was because I wanted to see you."

"W-What?" Asriel stammered.

 _What?!_ Chara snarled in her mind.

"How'd you know I'd be here?"

"I always knew you liked the opera," Frisk said, "and I figured that you might like seeing your old pal again. Gotta admit you've grown more handsome since I last saw you." She winked at him.

Chara felt her hands grow somewhat clammy, her eyes sparked with anger as her thoughts raced regarding Frisk's behavior. _Is she—she's_ flirting _with him?! She's actually flirting with Asriel? Asriel, my student, my Angel of Music?_ Her hands clenched, fighting to just knock something down in the hopes of scaring Frisk off—she didn't want to risk hurting Asriel too. "Back off, Frisky-bits," she snarled through gritted teeth. _"He's **mine**."_

A playful smirk lit up Asriel's face at Frisk's words. "So you're saying you couldn't help but stop and think of me?" he asked, unable to help but reference the song

"Of course, you goofball!" Frisk chided, giving her best friend a playful punch on the arm, grinning wider as he laughed.

"Well I'll tell you one thing," Papyrus exclaimed, "as far as I'm concerned, you're definitely hired! Starring performance!"

Asriel looked startled. "R-Really?"

"I'm sure you'll do great in it," Frisk said with an encouraging smile.

"Not just great," Papyrus added. "Fantastic!"

"You had a better voice than Mettaton, gotta admit," Sans chuckled, raising his hand for a high five. A little flustered, Asriel high-fived back.

"And don't worry," Frisk assured, taking the young monster's hand. "I'll be there."

Asriel looked sheepish as he rubbed the back of his neck, clearly still dazed that he was actually being accepted for the role and that Frisk was there as well. "Are you sure?"

"Positive. I'll definitely be there opening night!"

"Heh, thanks, Frisk..." He couldn't help but smile, his cheeks heating up from a blush of embarrassment.

Chara's heart sunk. Asriel didn't even seem put-off by Frisk's earlier flirtatious words! But she forced herself to try to not over-react, staying determined, as much as Frisk's presence angered her.

Knowing that there was no way she was going to get close to Asriel at this point, and with her mood completely soured from their behavior, Chara hurried through the back parts of the opera house, through the trap doors, descending down to the depths where no one knew about. Then again, if anyone knew just who lived down there, they'd likely stay away to begin with.

Racing through the darkness, her mind raced with a mixture of anger and confusion, feeling those emotions more strongly than anything in a while. Frisk and Asriel were simply friends who hadn't seen each other in years, this was probably the sort of thing friends did after being apart for ages. Playful bantering, nothing more. Not flirting, not anything resembling love...

Right?

How would Chara even know? She never even really had any friends like that. For all she knew it could just be normal friendly behavior. Not love.

 _It's fine... everything's fine... He can't feel affection toward her..._

* * *

Beneath the opera house, Chara was fuming. She paced around, feet scuffing the dirt floor and red eyes burning like angry coals, so bright she vaguely began to wonder if she could fire bursts of magic from them. But any dwelling on that was eclipsed by the mix of anger and despair that clawed at her heart and SOUL—what she had left of it. Every time she wondered if she had a SOUL anymore, feelings like this told her that she still did. She must, even if only in a fragment.

But this time, she _hated_ it.

"He _can't_ feel affection toward her!" she shouted, slamming her fist into one of the few shattered mirrors in this cavern. The glass cracked, tumbling to the floor, and her hand stung from the collapsed shards. But in that moment, she didn't care.

For once she had felt a glimmer of happiness this day, happy to see her student again after several months, and having gotten a starring role too. She had been so eager to talk to him, to congratulate him, to hear his wonderful voice...

And now he was chatting with a childhood friend he acted far too friendly with? Her being the newest patron, no less?

Asriel had to have felt some feeling for Chara herself, right? After all the time they had spent together, even if he never saw her face to face? And the young goat-monster had only mentioned this 'Frisk' a few times, like he had lost touch with her. Just a childhood friend and that was the end of it, with little to no bearing on his adult life. Let alone romantic pursuits.

And now here Frisk was. An old friend back in Asriel's life, pushing Chara away, and supporting the Opera and thus likely to spend quite a bit of time around it. Darn it.

"Something must have happened between them in those few months," Chara snarled. "They got back in contact, now they're acting all _sweet_ to one another." She gripped one of the music sheets from behind her organ, hands shaking as if ready to tear it in two.

But as her eyes glanced over the melody of the notes, she forced herself to take a deep breath and calm down. If anything, music was her one solace in this isolated place. Reluctantly, Chara placed the music sheet back onto the organ, focusing on the rhythm of the melody as music filled the chamber that she called home. But even as she tried to lose herself in the music, Chara's fingers curled as she played, nearly scraping the keys. Thinking of Asriel being with that other girl was really screwing with her concentration, slowing down until she was practically playing each note individually.

But maybe it wasn't as she thought. Her student and the patron hadn't kissed or anything—at least not that she saw. They could still just be friends...

Unable to focus on playing anymore, Chara stared at the organ before storming over to her bed over in the corner. The bed was dusty, a relic from the dump that no one had wanted, its faded red covers looking as if they were offering to help take her mind off things and just forget all her problems with sleep.

But Chara didn't feel at all relaxed, laying down on the bed before promptly slamming her head into her pillow, pressing the black mask more against her face. "This can't get worse," she mumbled.

Unfortunately, she was proven wrong the moment those words left her mouth, her head lifting up as she heard a voice. A high-pitched laugh. One she knew too well for her liking. _If I just ignore him,_ Chara thought, placing the ends of the pillow around the sides of her head as she lay on the mattress, _then he'll go away._

"Trying to ignore me, huh?" She could hear the shuffling of dirt, the friendly-sounding voice now sounding closer to her bed. "Not gonna work."

Chara opened her eyes, unfocused as she stared straight ahead but not looking at the speaker. Her gaze trained on her organ, Fixing her attention on it alone.

"I would think that you'd want to vent to _someone_ about what you saw up there. I know you were watching."

It was then that Chara finally responded, sitting up to face the speaker at the foot of her bed. "Go away, Flowey."

The being in question, literally a flower with a sunny expression, managed to poke his head just over the bed's edge, his round black eyes rising to a level where they could meet her own. He appeared warm and friendly, his yellow petals encircling his face like a miniature sun. But Chara knew better.

"Aw. Come on," the flower said too sweetly, petals spread out and his leaves shifting on his stem as if offering a handshake. "Don't you even have a few words to spare to your old friend?"

Chara flinched at the flower's words before lifting herself up from her bed and taking a few steps closer, leering down at him. "I have six words." Her eyes glinted dangerously behind her mask, and her voice was dripping with malice, nearly a snarl. " _Rot in hell, you damn flower._ "

Flowey's leaves curled close to his stem, shrinking back as if wounded, though his expression said otherwise. " _Ouch_ ," he said mockingly, that ever-present smile not leaving his face. "Threats like that aren't going to work with me. If I recall correctly, you said once..."

The flower paused in his speech as his face twisted into something completely different, and Chara instinctively turned her eyes away out of reflex. Flowey's face had turned into her own. Without the mask. She may have smashed all the mirrors in this chamber, but Flowey seemed to delight in bringing her true appearance to light even as she tried to hide it.

When Flowey spoke again, it was with Chara's voice as he echoed her own words from long ago. " _I'm already in my personal hell._ "

Chara's fists clenched, her nails digging deeply into her palms and stinging as she felt herself draw blood. She stormed over to her organ, sitting down at the bench and shuffling her music before placing her fists on the keyboard, a couple drops of blood dripping onto the keys.

"In any case," Flowey said, turning to his normal appearance and voice once more as he burrowed under the ground to pop up close to her again, "I would think that you'd be nicer to me after all I've done for you."

" _To_ me, not _for_ me," Chara snapped, not in the mood for taking anyone's crap, especially his. She faced the flower once more with a hostile glare. "You've had a strange idea of 'help' in the past."

"Still a master of twisting words, I see." Flowey popped his head below the worn ground, only to pop up again seconds later, nearly right next to her. "Remember when we met?"

"I try not to," Chara said. "And yet you keep popping up in my life." She turned swiftly away from him, her form hidden behind her organ.

"Of course, I should have expected that," Flowey said as if pleased, his leaves almost dancing like arms. "And don't lie. Who helped bring things here for you to retrieve when you didn't want to yourself? Because you _knew_ anyone would be terrified to see you?"

Red eyes lit up like old embers. "There's—"

"Whenever _she_ knew she couldn't be there without anyone finding you?" Flowey interrupted, his tone laced with warning as his head leered closer from his stem.

Chara fought not to cringe, trying to hide any sort of emotion, which to anyone else might have been easy thanks to her mask. But Flowey knew. He always seemed to know. "I didn't want anyone to follow me," she said, unclenching her fists. "If anyone found me down here—"

"Anyone except maybe that Dreemurr kid, right?"

Chara stiffened.

The flower laughed at her expression, even if only her eyes and mouth were visible. "I may not be able to get everywhere in the opera house like you can, but you've been teaching the kid awhile, and he's got some pipes." The flower rose himself upward, nearly eye-level with the so-proclaimed phantom. "Bet you felt pretty proud for once in your life when those numbskulls were actually impressed."

 _He's taunting me,_ Chara thought with a bitter scowl. _Not like I'd expect less_.

"And now Little Miss Frisk has shown up," Flowey went on, saying Frisk's name in a sing-song voice. "And you find her a threat, don't ya?"

Chara grit her teeth, but nodded slightly all the same. She had been so focused on the infuriating weed that she had nearly forgotten the reason for her bitterness today in the first place. She huffed, leaning over to look the smug flower in the eye as much as she could. "I told you years ago, _I don't need you._ "

"But don't I make everything a bit less..." the flower's face distorted from his friendly-looking smile to almost a skull-like appearance, his voice distorting as he did so, " ** _lonely?_** "

Chara slammed her hands on the organ's keys, standing up as she grit her teeth, nearly biting her own tongue as she snarled. "I don't care! _I'm better off alone!_ "

Her eyes scoured the area behind the organ, but the flower had gone without a sound, leaving Chara alone with her thoughts. She eventually let out a heavy sigh, leaning back in her chair. Her own words echoed in her mind.

 _I'm better off alone!_

In truth, she knew it was a lie. She wanted to have companionship, truthfully, more than anything in the world. And love. Not LOVE as Flowey saw it, as she had known it herself in the past, but someone showing genuine caring for her. But that was a route of life she had given up on long ago. With one exception—Asriel Dreemurr.

Asriel respected her, was always willing to talk to her, and only knew her by her voice. He had no idea of what she looked like, mask or no mask. Perhaps it was best if it was kept that way.

But despite everything, she wanted Asriel to see her. Well, not _all_ of her, never behind her mask... but at least see what she looked like for the most part. After all, if they were ever going to be together, the goat monster couldn't just have a relationship with a voice. He may never see what her face looked like—no one should—but at least he'd get to know her as a person.

Perhaps opening night of the performance would be the best time to approach Asriel Dreemurr face to face, so to speak. After making sure, of course, that a certain _human_ was out of the picture for the evening.

* * *

 **A/N: Wow, didn't expect the chapter to be this long. XD For the curious, Flowey does not have a direct equivalent in the Phantom-verse, in the sense that there's no character who was like a pestering entity who bothered the Phantom despite claiming to have been friends at one point. However, I guess you could say he's a bit of a mix between the Persian (a friend of Erik's who helped him out), and a character only referred to as "the brown man" in one scene, a hermit monk who lives in the sewers and Erik is more scared of him than he is of Erik. So I guess you could say that Flowey is a bit of a composite character of those two, bringing a bit of Leroux into this primarily Webber-based Undertale fic (though Chara's mask is Leroux based as well since it's black and covers her whole face). :) So, next chapter we'll get a bit more background info on Asriel and the "Angel of Music". If you've seen Phantom, you likely know where this is going to an extent. ;) See ya next chapter!**


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